Add Cham languages (cja, cjm) (#384)

It's one of the languages requested at
https://phabricator.wikimedia.org/T304386
with all those scripts.

It's also configured on translatewiki, but was
never added to language-data properly.

Autonyms according to this dictionary:
Abdul Majid Hj. Yunos (2010). Kamus Cam–Melayu Jawi Rumi

data/langdb.yaml

@@ -155,7 +155,15 @@ languages:
   chr: [Cher, [AM], ᏣᎳᎩ]
   chy: [Latn, [AM], Tsetsêhestâhese]
   ciw: [Latn, [AM], Anishinaabemowin]
+  cja: [cja-latn]
+  cja-arab: [Arab, [AS], چم فور]
+  cja-cham: [Cham, [AS], ꨌꩌ ꨚꨭꩉ]
+  cja-latn: [Latn, [AS], Cam pur]
   cjk: [Latn, [AF], cokwe]
+  cjm: [cjm-cham]
+  cjm-arab: [Arab, [AS], چم فاي]
+  cjm-cham: [Cham, [AS], ꨌꩌ ꨚꨰ]
+  cjm-latn: [Latn, [AS], Cam pai]
   cjy: [Hant, [AS], 晉語]
   cjy-hans: [Hans, [AS], 晋语（简化字）]
   cjy-hant: [Hant, [AS], 晉語（正字）]
@@ -889,7 +897,7 @@ scriptgroups:
   SouthAsian: [Beng, Cakm, Deva, Gujr, Guru, Knda, Mlym, Mtei, Olck, Orya, Rohg, Saur, Sinh, Sylo, Taml, Telu, Tibt, Thaa, Wara]
   Cyrillic: [Cyrl]
   CJK: [Hani, Hans, Hant, Kore, Jpan, Yiii]
-  SouthEastAsian: [Bali, Batk, Bugi, Java, Khmr, Laoo, Lana, Mymr, Thai, Tale]
+  SouthEastAsian: [Bali, Batk, Bugi, Cham, Java, Khmr, Laoo, Lana, Mymr, Thai, Tale]
   Mongolian: [Mong]
   SignWriting: [Sgnw]
   NativeAmerican: [Cher, Cans]

data/language-data.json

@@ -924,6 +924,30 @@
             ],
             "Anishinaabemowin"
         ],
+        "cja": [
+            "cja-latn"
+        ],
+        "cja-arab": [
+            "Arab",
+            [
+                "AS"
+            ],
+            "چم فور"
+        ],
+        "cja-cham": [
+            "Cham",
+            [
+                "AS"
+            ],
+            "ꨌꩌ ꨚꨭꩉ"
+        ],
+        "cja-latn": [
+            "Latn",
+            [
+                "AS"
+            ],
+            "Cam pur"
+        ],
         "cjk": [
             "Latn",
             [
@@ -931,6 +955,30 @@
             ],
             "cokwe"
         ],
+        "cjm": [
+            "cjm-cham"
+        ],
+        "cjm-arab": [
+            "Arab",
+            [
+                "AS"
+            ],
+            "چم فاي"
+        ],
+        "cjm-cham": [
+            "Cham",
+            [
+                "AS"
+            ],
+            "ꨌꩌ ꨚꨰ"
+        ],
+        "cjm-latn": [
+            "Latn",
+            [
+                "AS"
+            ],
+            "Cam pai"
+        ],
         "cjy": [
             "Hant",
             [
@@ -5482,6 +5530,7 @@
             "Bali",
             "Batk",
             "Bugi",
+            "Cham",
             "Java",
             "Khmr",
             "Laoo",
@@ -6385,7 +6434,8 @@
             "kaa"
         ],
         "KH": [
-            "km"
+            "km",
+            "cja-latn"
         ],
         "KI": [
             "en"
@@ -7180,7 +7230,8 @@
         "VN": [
             "vi",
             "zh-hant",
-            "zh"
+            "zh",
+            "cjm-cham"
         ],
         "VU": [
             "bi",